separation of diastereomeric 1,2-cyclohexanediols

Experimental Organic Chemistry: A Miniscale and Microscale Approach
Section 7.2 SEPARATION OF DIASTEREOMERIC 1,2-CYCLOHEXANEDIOLS
NAME (print):
INSTRUCTOR:
DATE:
LABORATORY SECTION:
1 . Indicate which of the following statements is true (T) and which is false (F).
a. trans-1,2-cyclohexanediol is a meso form.
b. The cis- and trans-1,2-cyclohexanediols are enantiomers.
c. The cis- and trans-1,2-cyclohexanediols cannot be separated by fractional crystallization.
d. (+)-trans-Cyclohexane-1,2-diol and (-)-trans-cyclohexane-1,2-diol have different
chromatographic adsorption properties.
2. Why should a TLC plate be removed from the solvent before the solvent front reaches the top of the plate?
3. Why should the developing chamber for a TLC plate not be open to the atmosphere?
4. What physical properties could be used to distinguish cis- from trans-1,2-cyclohexanediol?
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©2006 Thomson Brooks/Cole

Experimental Organic Chemistry: A Miniscale and Microscale Approach
5. Why might water not be an appropriate extinguishing medium for burning petroleum ether?
6. Identify any of the following diagrams that illustrate an improperly spotted TLC plate and explain what is
wrong in each such case.
a.
a. b. c. d.
Liquid level
b.
c.
d.
7. The flash points (°C) for petroleum ether (bp 60–80 °C), acetone, and 2-propanol are, respectively,
, , and .
8. List three of the possible effects of inhaling excessive amounts of acetone.
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©2006 Thomson Brooks/Cole